Figure 4-1. Normal chest cavity and lungs.
Note: Air flows into the chest cavity from a penetrating wound, collapsing the lung.
Figure 4-2. Collapsed lung.
SIGNS AND SYMPTOMS OF AN OPEN CHEST WOUND
An open chest wound can be caused by the chest wall being penetrated by a
bullet, knife blade, shrapnel, or other object. If you are not sure if the wound has
penetrated the chest wall completely, treat the wound as though it were an open chest
wound. Some of the signs and symptoms of an open chest wound are given below.
a. Sucking or hissing sounds coming from chest wound. (When a casualty with
an open chest wound breathes, air goes in and out of the wound. This air sometimes
causes a "sucking" sound. Because of this distinct sound, an open chest wound is
often called a "sucking chest wound.")